#### 19.14.3 Coping with browser quirks

If you click the Reload button on your browser with your OmniHelp system loaded, CSS style sheets might not reload, so the resulting page might appear unformatted. Browsers do not retain the original URL internally, and if you try to restart from the later-stage OmniHelp file the browser does recall, you miss loading several necessary JavaScript files. That is why DITA2Go provides a Start button. Use the OmniHelp Start button instead of the browser Reload button.

Likewise, never use the browser Back button; always use the OmniHelp Back button instead. When you load OmniHelp in Internet Explorer, this is not a problem, because Internet Explorer loads in its own window that does not have these problematic browser controls. Although you can do the same in Firefox, thanks to its “security” features, this works only when you are loading from the Web, not locally.

The most commonly used browsers on Windows each seem to have a different issue with displaying OmniHelp files:

Internet Explorer issues

Firefox issues

Chrome issues

Opera issues

Safari issues

Netscape issues

Internet Explorer issues

When you open an OmniHelp file in Internet Explorer, even if you have specified that the existing window should be closed (see §19.5.1 Configuring OmniHelp window usage and frameset dimensions), you get a confirmation dialog:

The Web page you are viewing is trying to close the window.

Do you want to close this window?

This is an Internet Explorer “security feature” that cannot be turned off. To avoid the confirmation dialog, your only real choice is to open OmniHelp in the existing window, with all the browser chrome on top. Or open in the new window, but leave the starting window open too, which looks like a mistake but is harmless.

Firefox issues

Firefox does not open a new window when you launch a local OmniHelp system by double-clicking _myproj.htm, unless you also set the following option in Firefox. On the main Firefox menu, choose:

Tools > Options... > Tabs > Open links from other applications in:

and check a new window. Unfortunately, all the chrome comes along with the new window.

For OmniHelp systems viewed on the Web, unless you have pop-up windows blocked, Firefox should open OmniHelp in a new window, without chrome. If you do have pop-up windows blocked, you can unblock them selectively; on the main Firefox menu, choose:

Tools > Options... > General > Block Popup Windows > Allowed Sites

and add the Web address where your OmniHelp system is located.

If you click Reload to refresh OmniHelp in Firefox, the left navigation pane might lose its CSS rendering. The workaround is to close the OmniHelp tab, then reopen OmniHelp from a Firefox bookmark that references _myproj.htm (see §19.14.1 Starting with the default topic or a specified topic).

Chrome issues

When you attempt to access Help files located in your local file system, OmniHelp (and all other forms of Web Help we know about) will not work in Google Chrome, unless you start Chrome with this special command-line switch:

    --allow-file-access-from-files

This option allows locally hosted Web Help systems to open in Chrome. Otherwise, Chrome does not allow local files to access the JavaScript scope of the parent frame/window. Because of security risks, users should start Chrome with this option only to view trusted local Web Help systems.

See Peter Grainge’s discussion of this issue, in Snippet 130:

http://www.grainge.org/pages/snippets/snippets.htm

Opera issues

On some systems, Opera works as expected with OmniHelp. On other systems, Opera might not display the left navigation pane. On still other systems, refresh eliminates the content of the contents, the index, and the search frame.

Safari issues

On an iPad, Safari does not seem to respect frame size settings. Instead the frame adjusts to the width of its widest contents.

Netscape issues

Later versions of Netscape Navigator might refuse to open OmniHelp files if you have suppressed pop-ups; on the Navigator Edit menu, look at Preferences... > Privacy & Security > Pop-up Windows. Also, later versions of Netscape Navigator might ignore CSS for OmniHelp files viewed over the Web. Local OmniHelp files, with local CSS, are displayed properly.

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Parent Topic: 19.14 Deploying OmniHelp

Sibling Topics:

19.14.1 Starting with the default topic or a specified topic

19.14.2 Restarting where you left off